local str1 = 'hello world'
local str2 = "hello lua"
local str3 = [["add\name",'hello']]
local str4 = [=[string have a [[]].]=]
local str5 = [[hello"]]
local str6 = [=[
  hello world
xxxx]=]
local str7 = [[fff
hello world
]]



print(str1)    -->output:hello world
print(str2)    -->output:hello lua
print(str3)    -->output:"add\name",'hello'
print(str4)    -->output:string have a [[]].

print(str5)
print(str6)
print(str7)